Seeing quite a few peasants who ladder to the sky, hide, and otherwise contribute little while pissing the most off.
If you have not read the peasant guide in the crpg section of the taleworlds forum, do so, and here's a few suggestions.
Your goal is to somehow contribute while being next to useless.
First and foremost, try not to screw up team mates.
Distraction. Be bait, some people seem enraged by peasants and will chase them - try and survive by blocking, running, whatever you can to tie up that knight's time until a team mate stabs him in the back. You don't have time to wonder if his rage stems from the scullery maid that gave him a dose and pissed in his porridge.
Protection. Without blocking a team mates movement, try and watch an archer's back - leap in the way of a charging horse if you must, but protect your chosen liege for the round.
Getting that little tap with your staff or wooden sword can often leave an opponent open for a killing blow.
If you take a weapon master at level 1, you can put 30 points into the weapon of your choice, leaving you with 31 - currently I am running around with 30 31 31 wpf in the melee weapons and finding it adequate. your problem at level 1 is lack of athletics (footwork) and power strike. Still, it is possible to get a kill at level 1, I seem to do it every third generation.
Positioning - like all low athletics builds, once you are out of position it is very tricky to get back into position, constantly scan the battlefield and work on your situational awareness. Call out enemy movements; this can turn the tide when a sneak flank is thwarted because you did not have your head exploring your rectum.
Taunts. Be creative, 'roleplay' some taunts.
Acceptance. It may be that as a peasant, you will contribute something key to team victory; it is assured that it will be unsung, unappreciated and un-noted, but YOU will know.